This application claims priority under 35 U.S.C. xc2xa7xc2xa7119 and/or 365 to patent application Ser. No. 0100250-0 filed in Sweden on Jan. 30, 2001, the entire content of which is hereby incorporated by reference.
The present invention relates to a tool holder for cutting inserts for chip removing machining, the tool holder comprising an insert seat, which comprises two side surfaces, against which side edges of the cutting insert are intended to abut when the cutting insert is mounted in the insert seat, and that the tool holder has members for clamping of the cutting insert in the insert seat or members for receipt of clamping members for the cutting insert.
In a leaflet from ISCAR, entitled xe2x80x9cISCAR""s New Clamping System for Profiling Toolsxe2x80x9d conventional prior art is shown, which is illustrated herein in FIGS. 9 and 10, as well as a further development of prior art, which is illustrated in FIG. 11 herein.
As is seen in FIGS. 9 and 10, in the prior art there is disclosed a three-point abutment. In case the cutting insert S is exposed to a force Fc1 acting from the right, see FIG. 9, the cutting insert S will abut at two points CP1 and CP2 against a stiffer side surface 100 of a holder 102 and at one point against a more resilient side surface 104. This is illustrated in FIG. 9 by an angle xcex41 formed between the cutting insert S and the more resilient side surface.
If the force Fc2 acting on the cutting insert S comes from the left, see FIG. 10, the cutting insert S will abut against the stiffer side surface at one point CP1 and at two points CP3 and CP4 against the more resilient side surface. This is illustrated in FIG. 10 by an angle xcex42 formed between the cutting insert S and the stiffer side surface.
Clamping of the cutting insert S is normally effected with a so-called rocking pin 106, possibly in combination with a top clamp. This has turned out to be insufficient in a number of applications, i.e., the position of the cutting insert is not fixed in the holder to a sufficiently high degree of accuracy. This is particularly valid for this elongated type of cutting insert where large movements of the insert occurs if the cutting insert is exposed to varying loads from differing directions, which is the case during, for instance, copy turning.
As is seen in the prior art illustrated in FIG. 11, the insert seat is provided with a self-adjusting wedge W which abuts against a side surface of the cutting insert, the wedge being movable and self-adjusting to the cutting insert so that a four-point abutment CP1, CP2, CP3A, CP3B is obtained. Since the self-adjusting wedge is movable, the fixation of the cutting insert in the insert seat will be inadequate for certain applications.
A holder for cutting inserts is previously known from EP 0 184 818, the holder having an insert seat, in which a cutting insert is intended to be received. A circular segment-shaped member, which can be swivelled, is arranged in one of the side surfaces which define the insert seat, said member having two abutment points on the side thereof faced towards the cutting insert. In principal, the device according to EP 0 184 818 works in a similar way as the prior art illustrated in FIG. 11.
A primary aim of the present invention is to provide a tool holder of the above-mentioned kind, where an exceptionally accurate clamping of the cutting insert in the insert seat is obtained, this notwithstanding that the cutting insert is exposed to varying loading during, for instance, copy turning. The consequence of this is increased dimensional precision through the use of the tool holder.
Yet another aim of the present invention is to ensure that the cutting insert is fixed in the insert seat by means of a so-called four-point abutment.
Another aim of the present invention is to ensure that certain readjustments of the insert seat should be possible in connection with wear of the insert.
The present invention relates to a tool holder for a cutting insert for chip removing machining. The holder comprises a base body which forms an insert-receiving seat comprising a first bottom surface and two side surfaces upstanding from the first bottom surface. The base body further includes a slot forming an extension of the seat and including a bottom surface disposed at a lower elevation than the insert-support surface.
Preferably, the base body includes a wing disposed on one side of the slot. The wing forms one of the side surfaces. A screw passes through a hole in the wing and extends transversely to a longitudinal direction of the slot. The screw is threadedly received in a hole formed in a side of the slot disposed opposite to the wing.